Millimeter microwave point-to-multipoint broadcasting systems, components and methods are widely used to broadcast content, including audio, video, multimedia and/or data, from a millimeter microwave transmitting station to a large number of millimeter microwave receiving stations. As used herein, the term “millimeter microwave” refers to microwave frequencies above approximately 10 GHz, and may include, for example, publicly available frequency spectra at 10, 18, 23, 24, 31, 38, 60, 70, 80 and/or 90 GHz. The publicly available frequency spectra at 23, 31 and 38 GHz may be particularly amenable to support the functionality of point-to-multipoint broadcasting.
One potential problem of millimeter microwave point-to-multipoint broadcasting systems, components and methods is commonly referred to as “rain fade”, which denotes the reduced coverage area that may be available from a transmitting station when raining. In particular, raindrops may provide significant attenuation of millimeter microwave frequencies. Thus, for example, absent rain fade, a millimeter microwave point-to-multipoint broadcasting system may have a coverage area of about 10 miles, whereas during rain fade, this coverage area may be reduced to about 1.5 miles.
U.S. Pat. No. 6,735,452 to Foster, Jr. et al., entitled System and Method for Broadband Millimeter Wave Data Communication, notes at Column 18, lines 28-42, that periodic adjustment of communication parameters may be necessary, even where an initialization algorithm has been utilized to properly initialize such communication parameters, because of the occurrence of anomalies effecting communication. For example, although an initial QAM rate and/or transmission power level may be selected upon initialization of communication, various atmospheric conditions, such as rain, may cause significant signal attenuation. Therefore, it is advantageous to monitor communication parameters to provide adjustment compensating for the occurrence of such anomalies. It shall be appreciated that the monitoring of communication parameters and communication of control functions may be from a node to a hub where such node has detected unacceptable communication attributes. Also see U.S. Pat. No. 6,016,313 to Foster Jr. et al., also entitled System and Method for Broadband Millimeter Wave Data Communication.
Moreover, U.S. Pat. No. 5,920,813 to Evans et al., entitled Microwave Video Distribution System and Adaptable Microwave Transmitting Station, describes, in the Abstract thereof, that in a cell of a microwave cellular video distribution system, e.g., a multichannel video distribution system operating at frequencies of around 29 GHz or 40 GHz, the transmitting antenna is composed of individual antenna sectors for transmitting the microwave signal towards different sectors of the cell. A respective monitor is present in each of the different sectors of each/the cell to monitor the microwave signal transmitted in that sector. The antenna sectors are individually fed through controllable feed means which permit individual control of the power level of the microwave signals transmitted by the individual antenna sectors, including the switching off of that sector. A feedback coupling is present between each monitor and the controllable feed means of the respective antenna sector to control individually the power levels transmitted towards the different sectors of each cell. In this manner the transmission pattern in each cell can be controlled and adapted to improve the quality of signal reception as requested by subscribers to increase the operational life of the transmitting station(s) by minimizing transmitting station power, and to enhance responsiveness to other desirable and/or acceptable demands placed on the signal transmission.